Conventional produce handling and sorting/sizing equipment include cups or other structures that travel along pathways in the conveying and sorting/sizing system and support individual pieces of produce as they are carried through the system. Typically, these systems have a photographic zone, a weighing zone and a sorting/sizing zone. The produce pieces are placed on individual cups, and first passed through the photographic zone to evaluate the condition and quality of the produce, and then passed through a weighing zone. The produce pieces are then transported on a conveyor from the weighing zone into an appropriate sorting/sizing area where they are separated according to size, shape, color, weight or other factors. Existing systems typically include a computer that analyzes each piece of produce by weight, size, and blemish to determine into which sorting table or bin the produce should be discharged from the conveyor. When a particular piece of produce arrives at an appropriate sorting table, the cup or other support structure holding that piece of produce is actuated by the system which may cause it to pivot or otherwise drop the piece of produce in that cup onto the sorting table below.
In a typical sorting/sizing system, the cups holding the individual pieces of produce are attached to continuous chains which carry them through the system. In some existing systems, the pivots on the cups holding the produce pieces are often activated using solenoids or other similar physical actuators. These solenoids are located along the tracks along which the cups are traveling, with at least one solenoid associated with each track over each sorting table. When the cup holding a particular piece of produce arrives over the sorting table that has been selected for it by the computer system, the solenoid for that table is briefly activated as the cup goes by. This causes an extension to protrude from the solenoid which contacts the cup causing it to pivot and drop the produce it is carrying. The solenoid then immediately retracts so as not to make unwanted contact with the next cup coming down the track. A plurality of parallel tracks with chains supporting the pivotable cups are provided in these systems such that a plurality of solenoids are needed on each track at each sorting table. The solenoids are provided on cross beams below the tracks of cups, and pairs of wires extend from the sides of the conveying system to each solenoid. Unfortunately, the continuous chains, the wires, the cross beams and the solenoids themselves provide numerous irregular openings and surfaces where contamination and debris may accumulate over time, especially when thousands of pieces of produce travel through such systems on a typical day. As a result, it is difficult to completely clean these systems. This increases the risk that contamination, including listeria or other pathogens, may be transferred to the cups, to the produce, and to consumers of the produce. Accordingly, there is a need for improved produce sorting and sizing systems having parts that may be more easily and thoroughly cleaned in order to prevent unwanted contamination of the produce.
Conventional sorting/sizing systems also suffer from maintenance and cleaning challenges. Existing conveying systems typically use roller chains to drive the system, which tend to stretch over time, resulting in variance in the timing and movement of the conveyor, and the cups or other support structures that are driven along the conveyor. Additionally, the roller chain is susceptible to rust if the conveying system is washed with water or aqueous solution, resulting in deterioration of the function of the conveying system and needed repairs. Deterioration and variance in the operation of the conveying system can easily lead to errors in sorting the produce, since such systems work at high speeds. As a result, there is an ongoing need to improve the durability and efficiency of such equipment.